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The role of serum uric acid as a predictor of stroke among the general Japanese population remains controversial. We conducted a prospective cohort study of 5235 men and 8185 women aged 40-79 years at baseline between 1985 and 1994 in four Japanese communities, who were initially free from stroke, coronary heart disease, and medication for hyperuricemia or gout. Cox proportional hazards models were used to estimate sex-specific hazard ratios of stroke and its types in relation to serum uric acid level. During a median follow-up of 23.1 years, we recorded 1018 (488 men and 530 women) incident strokes, including 222 (99 and 123) intraparenchymal hemorrhages, 113 (33 and 80) subarachnoid hemorrhages and 667 (347 and 320) ischemic strokes. After adjustment for age, community and known cardiovascular risk factors, the multivariable hazard ratios (95% CIs) in the highest vs. lowest quintile of serum uric acid were 1.45 (1.07-1.96) for total stroke, 1.20 (0.65-2.20) for intraparenchymal hemorrhage, 1.46 (0.69-3.09) for subarachnoid hemorrhage and 1.61 (1.07-2.41) for ischemic stroke in women. The corresponding multivariable hazard ratios (95% CIs) in men were 1.02 (0.74-1.35), 0.83 (0.40-1.72), 1.19 (0.38-3.75) and 1.00 (0.70-1.41). Furthermore, those positive associations with risks of total and ischemic strokes in women were more evident in nonusers of antihypertensive medication than the users. In conclusion, elevated serum uric acid level is an independent predictor of total stroke in women but not in men. The positive association in women was mostly attributable to ischemic stroke and was more pronounced among nonusers of antihypertensive medication.

This study aimed to assess the association of cigarette smoking with radial augmentation index among the Asian general population. We conducted a cross-sectional population-based study including 1593 men and 2671 women aged 40-79 years. Smoking status was ascertained through interviews, and the number of pack-years was calculated. The radial augmentation index was defined as the ratio of central pulse pressure to brachial pulse pressure, as measured using an automated tonometer: the HEM-9000AI (Omron Healthcare co., Kyoto, Japan). There was a higher prevalence of an increased radial augmentation index among current male smokers who smoked ≥ 30 cigarettes/day and all female smokers than among never smokers. After adjusting for known risk factors of atherosclerosis, the multivariable odds ratio (OR) [95% confidence interval (CI)] for a high radial augmentation index for current male smokers who smoked ≥30 cigarettes/day compared with never smokers was 1.9 (1.1-3.4). The multivariable OR (95% CI) for a high radial augmentation index for former female smokers and current female smokers compared with never smokers was 1.8 (1.2-2.7) and 2.5 (1.6-3.9), respectively. Moreover, smoking pack-years was positively associated with a high radial augmentation index in both sexes. There were no relationship between smoking status and high central or brachial pulse pressures among subjects of either sex. In conclusion, cigarette smoking and cumulative smoking exposure were positively associated with an increased radial augmentation index in men who smoked heavily and in women.

Limited information is available regarding risk of cardiovascular disease and trends for the metabolic syndrome in Asia. We examined the impact of the metabolic syndrome and its components on risk of cardiovascular disease among middle-aged Japanese according to four criteria. We followed 2,613 subjects from a rural Japanese community who participated in cardiovascular health examinations between 1990 and 1993. After 27,477 person-years of follow-up through 2003, there were 42 incidents of ischemic heart disease, 73 total strokes (54 ischemic and 18 hemorrhagic), and 115 total cases of cardiovascular disease. The metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII), American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI), International Diabetes Federation (IDF), and Japanese criteria. The multivariable hazard ratios (95%CI) associated with the metabolic syndrome based on NCEP-ATPIII criteria were 2.1 (1.1-4.0) for ischemic heart disease, 1.7 (1.0-2.7) for total stroke, 2.0 (1.2-3.5) for ischemic stroke, 1.1 (0.4-2.8) for hemorrhagic stroke, 2.0 (1.3-3.1) for ischemic cardiovascular disease, and 1.7 (1.2-2.5) for total cardiovascular disease. The population-attributable fractions of the metabolic syndrome based on NCEP-ATPIII criteria were 26-27% for ischemic heart disease and ischemic stroke and 20% for total cardiovascular disease. The metabolic syndrome based on AHA/NHLBI, IDF and Japanese criteria had weaker associations with risk of cardiovascular disease, and the association with risk of ischemic heart disease was not statistically significant. The metabolic syndrome based on NCEP-ATP III criteria predicted risks of ischemic heart disease, ischemic stroke and total cardiovascular disease, whereas that based on three other criteria predicted them less effectively.

application/pdf, Sleep-disordered breathing is a risk factor for hypertension, cardiovascular disease and accidents in the general population, but little is known about this correlation among professional truck drivers. To examine the relationships of sleep-disordered breathing with blood pressure levels and excessive daytime sleepiness among truck drivers, we conducted a population-based cross-sectional study of 1,313 subjects aged 20−69 years registered in the Japanese Trucking Association. The 3% oxygen desaturation index was selected as an indicator of sleep-disordered breathing, representing the number of desaturation events per hour of recording time in which blood oxygen fell by ≥3% by overnight pulse oximetry. The Epworth Sleepiness Scale was used to estimate excessive daytime sleepiness. There were significant positive associations between the 3% oxygen desaturation index levels and both diastolic blood pressure levels and Epworth Sleepiness Scale scores. The multivariate odds ratio of hypertension was 2.0 (1.1−3.6) for a 3% oxygen desaturation index of ≥15 in reference with a 3% oxygen desaturation index of

To examine the impact of age on the relationship between blood pressure (BP) levels and each of cardiovascular disease mortality and all-cause mortality, a total of 30,226 men and 58,798 women aged 40-79 years who had no history of stroke or heart disease underwent health checkups in Ibaraki-ken, Japan, in 1993 and were followed through 2002. Risk ratios for mortality by BP category based on the 1999 WHO-ISH guidelines were calculated by age subgroups (40-59 years, 60-79 years) using a Cox proportional hazards model. Compared with optimal BP levels, the multivariate risk ratios of cardiovascular mortality for stage 2 or 3 hypertension were 5.99 (95% confidence interval: 2.13-16.8) in middle-aged men and 4.09 (1.70-9.85) in middle-aged women. These excess cardiovascular mortality risks were larger in the 40-59 years age group than in the 60-79 years age group for both genders (p for interaction = 0.01 for both). In men, the population attributable risk percents of cardiovascular mortality were 60% for younger men and 28% for older men, while for women they were 15% for younger women and 7% for older women. Weaker but significant excess risks of total mortality were observed for stage 2 or 3 hypertension in men of both age groups and in the older age group for women. The impact of BP on the risk of cardiovascular mortality was larger among middle-aged persons than among the elderly in both men and women. Our findings indicate the importance of BP control to prevent cardiovascular disease among middle-aged individuals.

application/pdf, To examine the relationship between sleep-disordered breathing (SDB) and blood pressure levels among Japanese men, we conducted a population-based cross-sectional study of 1,424 men aged 40-69 years in rural and urban communities. The 3% oxygen desaturation index (ODI) was selected as the indicator of SDB, representing the number of desaturation events per hour of recording time in which blood oxygen fell by ≥3% according to overnight pulse oximetry. To estimate the associations of 3% ODI levels with blood pressure levels and hypertension, multiple linear regression and logistic regression analyses were performed. The 3% ODI level was positively associated with systolic and diastolic blood pressure levels (SBP/DBP); a 5 event per hour increment of the 3% ODI level was associated with 0.8 mmHg (95% confidence interval [CI], 0.0-1.6) greater SBP and 0.7 mmHg (95% CI, 0.3-1.1) greater DBP after adjustment for age, body mass index, ethanol intake, smoking category and community. The multivariate odds ratio of hypertension for the low vs. high category of 3% ODI level was 1.63 (95% CI, 1.1-2.5). These associations were more evident among overweight than non-overweight individuals. The significant association of nocturnal oxygen desaturation with high blood pressure levels suggests that SDB plays a role in the development of hypertension among Japanese men.

application/pdf, Evidence on the effect of salt intake on the interaction between angiotensinogen (AGT) T174M polymorphism and high blood pressure is sparse. We therefore conducted a large population-based cross-sectional study of 2,823 men and women aged 30-74 in a Japanese farming community to examine associations between AGT polymorphism and blood pressure levels stratified by age (30-64 and 65-74), body mass index (BMI; median), and salt intake (median) estimated by 24-h urine collection and dietary questionnaire. Our a priori hypothesis is that individuals, particularly younger and non-overweight individuals, with the 174M allele have elevated blood pressure levels in response to higher sodium intake, and thus the association between T174M polymorphism and blood pressure is more evident among individuals with higher sodium intake than those with lower sodium intake. There were no differences in systolic or diastolic blood pressure levels (SBP or DBP) between the TT and TM+MM genotype groups overall. However, the mean difference in DBP between the TM+MM and TT groups was +1.0 mmHg in subjects of younger age (p =0.06), +1.7 mmHg in non-overweight subjects (BMI

To examine the relation between cigarette smoking and risk of stroke and coronary heart disease among Japanese, we conducted a 14-year prospective study of 3,626 men aged 40-69, initially free from history of stroke and coronary heart disease. We identified 257 strokes (75 hemorrhagic and 173 ischemic strokes) and 100 coronary heart disease events. When we adjusted for age and other cardiovascular risk factors, a significant excess risk among current smokers of > 20 cigarettes/day vs. never-smokers was found for total stroke (relative risk (RR) = 1.6 (95% confidence interval (CI), 1.1-2.4)). The excess risk of total stroke was particularly evident among hypertensives (RR = 2.3 (1.2-4.4)). The multivariate RR of ischemic stroke was 1.6 (1.0-2.5) for total subjects, and 2.2 (1.0-5.0) among hypertensives. Significant excess risks among current smokers of > 20 cigarettes/day vs. never-smokers were also found for coronary heart disease (RR = 4.6 (1.6-12.9)) and total cardiovascular disease (1.9 (1.3-2.7)). The estimated proportion of the events attributable to current smoking was 30 (95% CI, 11-44)% for total stroke and 34 (5-54)% for coronary heart disease. In conclusion, current smoking of > 20 cigarettes per day increased the risk of both total stroke and ischemic stroke among Japanese middle-aged men, and particularly among middle-aged hypertensive men.